Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Divasibranchia Minichev & Starobogatov, 1975
       Order Stylommatophora Schmidt, 1855 see Infraorder Stylommatophora Schmidt, 1855
         (Helicid Sigmurethra)
           Superfamily Helicoidea Rafinesque, 1815
             Family Helminthoglyptidae Pilsbry, 1939
               1 Genus Cahuillus Roth, 1996
               2 Genus Maricopella Roth, 1996
               3 Genus Nicolenea Roth, 1996
               4 Genus Noyo Roth, 1996
               5 Subfamily Helminthoglyptinae Pilsbry, 1939
               6 Subfamily Xanthonychinae Strebel & Pfeffer, 1879
               7 Subfamily Cepolinae Ihering, 1909, nom. illeg. see Family Cepolidae Ihering, 1909, nom. illeg.